drawbaugh



2 Sheets-Sheet (No Model.)

Pmntedjsept. 12, v189%. I

2v B. Si. .HM

DDR'AWBAUGH. PNEUMATIG TOOL [1,1 hvnw l (No Model.) 2 Sheets-Sheet 2.

' D. DRAWBAUGH.

PNBUMATIG TOOL Patented Sept. 12, 1893.

UNITED STATES PATENT OFFICE.

lPNEIIMA'rIc AND ELECTRIC TOOL COMPANY, OF NEW YORK, N.

PNEUMATIC TOOL.

SPECIFICATION forming part of Letters-Patent No. 504,802, dated September 12, 1893.

Application tiled December 5, 1892. Serial 454,096. (No model.) V

.To all whom t may concern:

Be it known that I, DANIEL DEAWBAUGH, of Eberlys Mill, in the county of Cumberland and State of Pennsylvania, have invented cer- 5 tain new and useful Improvements in Pneumatic Tools; and I do hereby declare the'following to be a `full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification,'and tothe letters'ot reference marked thereon. v p

This vinvention relates to improvements iu pneumatic tools such for instance as illustrated and described 'in my prior patent, N o.

li 5 472,495, dated April 5, 1892, to which reference `is hereby made, although the specic lfeatures constituting this invention are applicable to other tools of this class as will -bereadily understood by those skilled in the art. zo It is well known that tools of this kind, in order to be a practical'success must not only be compact;v and of small diameter for a tool of given power, but the air ports and passages must be so arranged as to permit the lair or other motive'fiuid to act promptly in performing its work and not be liable to clog K or foul up with accumulationsof oil, tine.

Now, it is the object of this invention, to provide a tool having an extremely simple arrangement of air ports with comparatively short passages connecting the same, and to provide for a stronger and more effectual forward stroke of the hammer or piston than has heretofore been deemed practical, with a comparatively light backward stroke, whereby the efficiency of the tool is greatly iucreased witliout increasing proportionately the vibration which is found prejudicial.

The invention consists primarily in a double or hammers connected rigidly together to form a single hammer, whereby-the surface exposed to pressure during the forward stroke of the hammer is greatly increased Without increasing the diameter' of the hammer ortool. The invention further consists incertain novel details of construction andcombinations and arrangements of parts to be hereinaf ter described and pointed out particularly 5o in the appended claims. v

Referring to the accompanying drawings:

substantially right angles to Fig. 1 and shownecessaI-y; suiiiceth ,to say that, B indicates 8o the said valve casing or box, b the live pressinterior of the box; and h2, b2 the ports in saidv v 9o p The cylinder is formed immediately below or tandem arrangement of pressure surfaces,i

'in the cylinder under the influence of air ad- Figurel is a sectional View taken through a tool embodying my invention and showing the passages leading to opposite ends of the cylinder. Fig.' 2is a partial section and ele- 55 vation lshowingihe ports and passages controlling the pressure supply and exhaust for the valve. Fig. 3 is a similar view with the piston or hammer at the opposite extreme of its'movement. Fig. 4 is a section taken at 6o ing the exhaust ports and passages for the piston and valve and a modified form of nose, piece. Fig 5 is a detail perspective of a'tool or chisel.

Like letters of reference in the several iig.- ures indicate the same parte As in said former patented device, a hammer or piston and the valve with its casing are preferably arranged in alignment within 7o a cylindrical main case or shell A,'and the' valve with itsfcasing is similar in all respects to said prior device, except that in this iu-y stance the live air passage for supplying pressure tothe intermediate ports of the pis 75 ton for distribution to opposite ends f the valve, is entirely omitted. Hence no particu lar description of the valve or ofthe arrangen ment of ports and passages in its exterior is ure-passage having ports b', b leading to the box for distributing the air to opposite ends of the piston or hammer. l l

b3 is'the exhaust port registeringwith an exhaust passage B3 in the casing A, and b, b5 are theports leading to opposite ends ot'- the valve box for supplying pressure to operate the valve.

the valve chamber for the reception of the piston or hammer, which in this instance, consists of a. in ain hammer portion lettered Cv and an auxiliary hammer portion -or piston 95 lettered C connected with -themain portion by a reduced stem C2, the whole constituting a rigid hammer adapted to reciprocate withmitted through the passages 'and ports as will ico be presently described. Surrounding the'stem C2 is aeollar or abutmer plays ment, which' in the preferred construction, where the piston orhammer is turned up from an integral piece, consists of a split collar D inserted within the lower end of the casing' and seating against a shoulder d formed 1n the cylinder. The anxiliarypiston or n' in the forward end of the cylinder and in this construction l have arranged the portion of the cylinder in which the auxiliary" piston works .inthe nose piece E ofthe' tool for the sake ofl convenienceof construction. This`jnose piece E, screws on to and forms a portion of the main casing. Hence in speaking of the main casing in it will be understood thatI refer to all the exterior parts necessary forinclosing the working parts. A passage leads from the lower end of the main portion of the cylinder or from a point belowvthe main portion of the piston upfo the uppermost of the ports b?, ing pressure below said piston or effect the ret urn stroke and-a passage f leadfor. conveying directly into the upper end of the cylinder' Afrom the lower port b serves to admit press n re vto the upper end of the cylinder for advancing the piston or hammer to give its effective stroke. Now in l order to supply the `pressure simultaneou sly to the' upper side of the main and auxiliary sections of the piston 'stroke is secured "is delivered which would be deliveredby a piston or hamor hammer the passage .G is preferably formed extending directly through the longitudinal center of the hammer or piston and stem C? and-opening out immediately above the auxiliary section of 'said hammer. Thus,

pressure admitted to the passage f acts not only on the upper end of the piston or hammer but, passing `through thepassage G acts simultaneously upon the upper surface ofthe auxiliary section. Hence the advance stroke with a strength equal to 'that mer of twice the superficial area or piston surface less the cross sectional area of, the stem C, and that'without increasingthe` diameter of the tool in the least. -The return by; pressure admitted through the passagef to the lower surface of the main section of the hammer which-being .4 small-area givesv a slight stroke on the return movementg'theintenslty ofwhich is further lessened by the air-cush.

ion yat the upper end asdescribed'in the bef' fore mentioned patent. Obviously, the piston or hammer may be made lin *sections screwed together in the ordinary well known mannerand the collar D maybe formed integral without departing from the spirit of my invention.. The forward end of the'hammer is preferably shaped to give a good ing or strengthening surface as by giving as shown and the nose piece is formed with a straight opening directly in line with said hammer. A tool inserted through this open-V ing will be struckby the hammer as shown for instance in Fig. 1 and the power .imparted utilized in any desired manner.

for instance through which a transverse pin h hamv broad terms,.-V

hammer tothe same a slightly convex shape In the preferred construction the shank H of the tool is formed with a peripheral groove in the nose of the beaterfmayvpass'to ret-ain the tool in position while permitting it to have a limited longitudinal movement under the action ofthe hammer and in order to facilitate the insertion and removal of the tool a section of one side may be cut away or flattened /as at H thus allowing it topass the pin h and when seated a 'slight turn will prevent its escape.

In some instances it may be desirable to employ a construction 'in which the hammer does notcome directly into .contact with the tool, and to accomplish washer, such as I, Fig.

4, may be inserted in 'the nose of the tool with alongitudnally movable button'i mounted therein and heid in place by it's enlarged head i. located beneath the washer; The stem of the button projects a very slight distance into the cylinder and is adapted to be struck by the hammer or piston and to'impart its motionto the tool shank which rests against its head or outer portion.l In both instances, it will be understood, that I, preferablyY provide no air passage from the .valve to the lower side of ,the auxiliary tion C' of the' hammer and in order to prevent any possible retardation of the hammer in its upwardrno'vement, the opening through which the tool and button enter .is of suiiicient size to permit. the air to enter freely below the hammer. With' this lconstruction it will b e seen, that when the valve..is reciprocated pressurewill be alternately admitted above and below. the hammer, causing the same to. reciprocate witha heavy forward stroke and light return and-in order to operate the valve itself and control its movements through the movement of the hammer, passages L, L', leading respectively from the uper Iund lower ports of the valve box, extend down through the casing and terminate in ports l' l' and l Z. These ports l l' are so located as lthat when Vthe hammer isst its upper extreme of movement with .pressure below it, one of thev ports l will benop'en to the cylinder below the hammer, admitting pressure tothe upper end of the valve, thereby reversing the valve and driving the hammer to 'the opposite extreme of its movement. When in this latter position, i. e., forward, asshown in Fig. 3, one ot the ports l will be open to pressure in. the -cylinder above the hammer and the valve will be consequently driven to ports vl l are so positioned that they are unthe" hammer reaches its extreme of movement, hence the valvezis not thrown until the effective stroke of the hammer has been given. .The exhaust for the valves is preferably also controlled by the hammer and for this purpose the hammer, in the construction shown, is provided with two centrally arranged circumferential channels or grooves M, one or the other of which oomthis desirable end, a

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the opposite extreme of its movement. The

municates with the centrally arranged exhaust port N when the hammer is at each eX- treme of its movement. The channel M not in communication with the exhaust port or passage N is in communication with one of either of the ports Z Z at the moment when the port leading to the opposite end of the valve is open to pressure in the cylinder. It will be noted particularly, that the channels or grooves M extend entirely around the hammer and a spline or other device for preventing the rotation of the hammer is unnecessary for the ports and length of the hammer are so positioned and proportioned that at no time can the passages LL be simultaneously in communication or open to the exhaust or cylinder above and below the hammer. In other Words, the moment the hammer begins its movement in either direction the ports leading from the passages L L are out off until the lhammer reaches almost vthe opposite extreme of its movement when one port is open to exhaust and the other port to the end of the cylinder receiving pressure.l

A tool constructed in accordance with my present invention will be found to have a much more powerful stroke for a given size or diameterof hammer than those heretofore constructed, rendering the tool much more efficient and greatly extending its field of usefulness. Y

Besides the efficiency secured by the double or tandem arrangement of'hammer the air ports and passages for controlling the valve are greatly simplified, one passage and corresponding ports, namely that leading from the constant source of pressure to the center of the hammer, being entirely dispensed with. By dispensing with this latter passage and port it-is found that the hammer is more evenly balanced because during its reciprocation there is no pressure of any consequence at any point in its periphery tending to force it against the opposite side of the cylinder.

Having thus described my invention,what I claim as new is- 1. In a pneumatic tool, the combination with the casing having two cylinder chambers formed therein, the valve and air supply passages from the valve, communicating with the upper ends of both chambers, of the loose piston or hammer having separate piston heads working in said cylinder chambers whereby the superficial area of both heads is utilized in the forward stroke; substantially as described.

2. In a pneumatic tool, the combination with the shell or casing having the cylinder formed therein, and the collarformed separate from and inserted in said cylinder for dividing the same into separate cylinder chambers, of theloose hammer formed by the pistons working in said cylinders, and connected rigidly together by the red uced stem workin g through the collar; substantially as described.

3. In a pneumatic tool, the combination with the shell Yor casing having the cylinder formed therein and the removable collar dividing said cylinder into separate cylinder chambers, of the loose hammer formed by the piston working in said cylinders connected rigidly together by the reduced stem working through the removable collar; substantially as described.

4. 4In avpneumatic tool, the combination with the shell or casing having the cylinder opening formed therein, removable collar dividing said cylinder into separate cylinder chambers, and the removable nose section for holding said collar in place, of the piston Workingin said cylinder chambers and the reduced stem passing through the collar and uniting the piston to form a rigid hammer; substantially as described.

5. In a pneumatic tool, the combination with the casing having the cylinder formed therein, the forward or nose section having a cylinder formed therein and a collar separating said cylinders, of the loose hammer having piston sections workin g in said cylinders and air ports and passages leading to therespective cylinder chambers; substantially as described. l

6. In a pneumatic tool, the combinatio with the casing having the separate cylinder chambers formed therein in alignment, of the hammer having piston sections Working in said cylinders respectively, a valve and air passages for conveying pressure to the upper portions of both cylinder chambers and the lower portion of the upper chamber, substantially as described.

7.In a pneumatic tool, the combination with vthe'casing having the piston chambers formed therein in alignment with each other,

of the hammer having piston sections working I in said chambers withapassage in said hammer leading to the lower chamber for supplya valve chamber formed in alignment therein with passages leading from the valve chamber to opposite ends of the upper cylinder chamber, of the valve and the hammer having pistons sections working in said cylinder.

chamber and a central passage for opening communication between the'upper endsof the respective cylinder chambers; substantially as described.

l0. In a pneumatic tool, the combination with the casing having the cylinder chamber IIO IZO

formed therein, the collar seating in said chamber and the nose section screwing on the casing for holding said collar in place and having the cylinder chamber and tool opening formed therein, of the hammer having the piston sections Working in the respective cylinder chambers,a valve and air passages leading from said valve to the upper ends of both cylinder chambers and the lower end ot` the upper cylinder chamber; substantially as described. A

11. In a pneumatic tool, the combination with the casin g and hammer, substantially as described, of the nose section having the tool opening therein, the pin or projection in said opening and the tool shank having the peripheral groove co-operating With said pin or projection; substantially as described.

12. In a pneumatic tool, the combination with the casing having the nose section with the tool opening formed therein and the pin or projection projecting into said opening, of the tool shank having the peripheral groove co-operating with said pin or projection, one side of the tool shank above said groove being cut away to permit the tool to enter past the projection; substantially as described.

13. In a pneumatic tool, the combination with the casing having the cylinder and pressure actuated valve, of the hammer having a circumferential chamber extending entirely around the same, passages leading from opposite ends of the valve to points at the upper and lower ends of the cylinder and terminating in points 15,75 and t t', and an exhaust opening for communicating with the central circumferential chamber ot` the hammer, said hammer and the ports leading to said passages being so proportioned and positioned with relation to each other that when the hammer is at the upper extreme of its movement, pressure will be admitted from the opposite end of the cylinder to one end of the valve and the opposite end of the valve will be open to exhaust through the circumferential chamber in the hammer and vice versa; substantially as described.

14. In a pneumatic tool, the combination with the casing having the cylinder therein and the pressure actuated valve, with passages leading from opposite ends ot' the valve to opposite ends of the cylinder respectively with ports Z Z and Z Z leading from said passages into the cylinder, of the hammer working in the cylinder and having the central circumferential chamber M extending entirely around the same and the exhaust passage N adapted to communicate with the said circumferential chamber; substantially as described.

l5. In a pneumatic tool, the combination with the casing and hammer working therein and the point section having the central opening for the reception of a tool shank, of a loose button mounted in the upper end of said opening and adapted to be struck by the hammer and impart its movement to the tool shank; substantially as described. l

16. In a pneumatic tool, the combination with the casing, hammer mounted therein and nose section having the central opening for the reception of a tool shank, the washer held by said nose section and the headed button loosely mounted in the Washer in line with the tool opening and adapted to be struck by the hammer, substantially as described, whereby the impact of the hammer is imparted to the button and through it to the tool shank; substantially as described.

DANIEL DRAXVBAUGH.

Witnesses:

ERNEST MARX, J. WILKINs ARMSTRONG.

is hereby certied that in Letters Patent N o. 504,802, granted September l2, 1893, upon :the application of Daniel Drawbaugh, of Eberlys Mill, Pennsylvania, for an improvement in Pneumatic Tools, an error appears in the printed specification requiring the following correction, viz.: In line 35, page 4, the Words and reference letters i points t t and tt 7 should read ports ZZ and lt andthat the said Letters Patent should be readA with this correction therein that the same may conform to the record of the case in the Patent Ofce.

Signed, countersigned, and sealed this 3d day of October, A. D. 1893.

[SEAL] WM. H. SIMS,

First Assistant Secretary of the Interior. Oountersigned:

S. T. FISHER,

Acting 0onmnsstonenA of Patents.Y 

